How Bad Is It Really to Do Planks When You’re Pregnant?

Pregnancy drastically changes your body to support your growing baby. That also means it changes the way you work out — especially the way you train your abs. As your uterus expands, your rectus abdominis (the superficial ab muscle covering the front of your belly) stretches.

At best, this means your abs aren't operating at full strength. And in some cases, the pull on the rectus abdominis and the linea alba (the tissue that connects the left and right sides) is so strong that your abs separate. This is known as diastasis recti, Heather Irobunda, MD, a board-certified obstetrician-gynecologist based in New York City, tells LIVESTRONG.com.

According to a September 2016 study published in the ​British Journal of Sports Medicine​, which followed 300 women during their first pregnancy, approximately 32.6 percent developed diastasis recti at 21 weeks, and 60 percent developed it six weeks postpartum.

Individuals who are older when they get pregnant, have a higher BMI, have had multiple pregnancies or are carrying twins or triplets are at a higher risk of developing diastasis recti during or after pregnancy, Dr. Irobunda says. Also, the weaker your abdominal muscles are, the greater the risk.

"Most women will experience some degree of abdominal separation during pregnancy, however, modifying the way you exercise can help decrease the severity of separation and improve recovery," Jodie Horton, MD, a fellow of the American College of Obstetricians and Gynecologists (ACOG) and chief wellness advisor at Love Wellness, tells LIVESTRONG.com.

So you won't need to sideline your core workouts completely, but you should modify them based on your specific pregnancy needs and as your due date approaches.

Given that your ab muscles get progressively weaker as they stretch during pregnancy, you might be wondering whether it's safe to do planks — or any ab exercises at all.

In general, Dr. Irobunda says it's safe to do planks during your first trimester if you were already doing them prior to getting pregnant and you have no contraindications (i.e. you're not at risk for or have been diagnosed with diastasis recti). In fact, as long as you're cleared for exercise, doing planks can actually help keep your core muscles strong and help prevent diastasis recti, she says.

However, as your belly grows, "you may want to consider moving on from planks if you notice that there isn't much space for your belly between the rest of your body and the floor while doing planks or if you feel unsteady while doing them."

Whether you're continuing an existing workout routine or starting a new one during pregnancy, here are a few other things you should know about including planks in your regimen.

Planks put weight directly on your abdominal muscles, Andrea Speir, founder of Speir Pilates and pre- and postnatal fitness specialist, tells LIVESTRONG.com.

"As your baby grows, your abdominal wall begins to get thinned and stretched out with the weight pressing down on it. If you hit a plank position, you are putting weight directly onto the thinned and stretched muscles," she says.

So while doing standard planks during your first trimester when your baby weighs less is usually fine, you'll want to swap them out for something else as your baby grows into the second and third trimesters because of the risk of abdominal muscle fatigue, Dr. Horton says.

Lower back pain is a common complaint during pregnancy. That's because, as your belly expands, your center of gravity shifts, altering your posture and putting more strain on your lower back, according to the ACOG.

"When performing planks during pregnancy, you run the risk of injuring your back due to the strain the baby bump can put on your body, particularly your back," Dr. Horton says. "If you don't perform the exercise with proper form or don't have good core strength, your body will engage the back muscles to hold your body in position. This creates a strain on the muscles in your back and possibly injury."

In addition, when you're pregnant, the ligaments in your back start to stretch to prepare for a growing belly, making them more prone to injury. And because you need to fully engage your core muscles in a plank — which are already weakened by pregnancy — it can be difficult (if not impossible and inadvisable) to draw your abdominal muscle in, which means your lower back takes another hit.

"The pelvic tilt and downward weight when doing a plank can pull at the lower back," Peel says. "Everyone is unique, but I would say by the end of the second trimester or the start of the third trimester, planks are not a good idea unless they are elevated."

Speir adds: "If you have any signs of diastasis recti or struggle with a swayed back [pelvis tilts forward], avoid all plank variations, such as mountain climbers and push-ups." Instead, she recommends trying a plank from your knees to avoid the direct gravitational pull on the abdominal muscles and lower back.

Just because you'll need to modify your ab workouts during pregnancy to keep you and your baby safe and allow for more comfort in your abdominal area, it's no excuse to skip training your core altogether.

"It's so important to keep your abdominals strong during pregnancy because it will help your body throughout the pregnancy, during labor and with postnatal recovery," Speir says. "You need that muscular strength to help support your spine and pelvis as the growing weight of your baby starts to pull your body forward and shift the balance of weight and pressure on your joints."

A strong core is also key for pushing during labor. "The oblique muscles are especially important at this point to help wrap around your midsection and help push during contractions," Speir says.

It's generally safe to exercise during pregnancy once you get the green light from your obstetrician, especially if you're healthy and don't have any complications, per the ACOG. In fact, exercise during pregnancy can help decrease your risk of gestational diabetes, preeclampsia (high blood pressure) and Cesarean delivery. It can also help ease constipation and back pain.

Despite not being able to do certain plank variations for the entirety of your pregnancy, there are plenty of other ways to train your core. As Peel suggests, doing elevated planks on a couch, bench or wall is completely safe and recommended.

Here are a few additional ab exercises Speir and Peel recommend to keep your core strong. Suitcase and front rack carries are essentially standing planks without the extra intra-abdominal pressure, while side planks strengthen the obliques and frogs target the lower abs.

1. On a yoga mat, lie on your left side with your left forearm on the ground and your shoulder over your elbow.
2. Extending your legs straight out and squaring your hips over each other, stack your right leg on top of your left. Keep your right hand on your hip.
3. Pushing through your feet and left forearm, lift your hips off the ground so you form a straight line from your feet to your shoulders. Avoid rotating your hips out to the sides or dipping them.
4. Hold for 30 seconds, then switch sides.

1. Lying face-up on a yoga mat, prop yourself up onto your forearms with your hands flat on the ground by your sides. Bend your knees and pull them toward your chest.
2. Pressing your lower back into the ground, extend your legs straight out in front of you to a 45-degree angle.
3. Bend your legs back in, pulling in through your abs. Complete 12 reps.

1. Get into an elevated plank by placing your hands shoulder-width apart on a bench, couch or other elevated surface and your feet on the floor. Make sure your shoulders are stacked over your wrists.
2. Tightening through your entire body, slowly lower your chest toward the bench. Keep your shoulders down and back and away from your ears.
3. Pressing your hands firmly on the bench, push yourself back up to an elevated plank with your arms full extended.
4. Aim to work for 30 seconds.

1. Tie a long looped resistance band to an anchor point, such as a pole, stair railing or similar object, at chest height.
2. Step a few feet away from the anchor to the side and hold the free end of the resistance band with both hands at your chest, creating tension in the band.
3. As you exhale, push the band away from your chest and straighten your arms in front of you. Engage your core muscles to prevent the band from pulling you toward the anchor point and avoid rotating your shoulders.
4. Then, bring the band back in toward your chest.
5. Aim to work for 30 seconds.

1. Using a pair of dumbbells or kettlebells, hold one weight in each hand with your arms down by your sides. Stand with good posture, keeping your spine tall, chest proud and your shoulders down and back. Engage your forearms and triceps to grip the weights and prevent them from touching your thighs.
2. With your feet shoulder-width apart and arms at your sides, begin walking forward. Remember to engage your core and pack your shoulders back and down.
3. Continue walking while maintaining good posture. Increase the number of steps or time spent as you get stronger.
4. Aim to work for 30 seconds.

1. Hold one dumbbell or kettlebell in your right hand at your shoulder, stacking the weight over your wrist with elbow pointing down. Stand with your feet hip-width apart and tighten your core.
2. Keeping your spine tall and chest proud, lift one foot off the ground, bending the knee and pulling it toward your hip.
3. Put your foot back down on the ground and lift the opposite foot, bending the knee and pulling it toward your hip. Avoid leaning to one side as you march by keeping your shoulders square and pressing the standing leg into the ground.
4. Aim to work for 30 seconds.

Ultimately, planks are great core-strengthening exercises that you can continue to do safely during your first trimester if you feel comfortable and you have no complications or warnings from your doctor. But as you progress in your pregnancy, you may want to hold off, as they can put additional pressure on your already weak abdominal muscles.

However, there are plenty of other ab exercises you can do to stay strong throughout pregnancy and after giving birth. It's important to keep an open dialogue with your doctor about your workout routine and discuss any concerns you have.

"If you have questions, concerns or unusual physical symptoms during a plank, talk to your doctor and follow their advice on what you should be avoiding at this point," Speir says. "I tend to be very conservative with my approach to prenatal exercise. I think it's incredibly important to do throughout if your doctor approves, but I also believe you need to listen to your body day by day."